Merged paths

Merged paths view is a tool for examining how objects are retained.
It is especially useful for analyzing objects of classes with a great number of instances, such as
int[], System.String etc.

Merged paths is similar to Paths from GC roots;
however, it does not show paths through individual objects, but paths from multiple objects grouped by class.

For example, see the picture below.
It shows that the memory held by Hashtable/bucket[] instances is mostly retained by
Hashtable instances, which are in turn retained by
CopyOnWriteHashtable and BuildItem.

Another difference between Merged paths and Paths from GC roots
is that the merged paths are build on the dominator tree
while the paths use the full object reference graph as is.
This means that some intermediate nodes seen in Paths from GC roots may be missing
in Merged paths for objects which are retained indirectly.